Sewer cleaning rodding machines have a rod holding reel mounted on a carriage and a rod feed unit mounted for rotation with the reel. The rod feeding system is driven by a hydraulic motor mounted on and turning with the entire reel mounting carriage. The carriage is independently rotated by a hydraulic motor mounted on a main support frame. Such systems are known and described in U.S. Pat. No. 3,176,335 and U.S. Pat. No. 3,393,415 incorporated herein by reference. These patents disclose such a machine and also disclose a reel arrangement for storing and feeding rod to the rod feeding system.
The rotatably mounted reel provides storage for the cleaning rod when not in use and imparts rod rotation by rotation of the carriage it is mounted on. A variety of sewer tools may be mounted on the end of the sewer cleaning rod which is fed into a sewer to clear obstructions from blocked or clogged sanitary, storm or sewer lines. In present systems experienced rod operator personnel are required and are hard to find. Because the operative events occur in a conduit well beneath the surface, and invariably far from the operator, it takes a good deal of experience before operators can determine how much pressure can be applied to the sewer cleaning rod without resulting in breakage or damage to tools attached to the rod and even injury to personnel. This is because he is so far from the operative situation. Even with experienced personnel, losses due to down time, tool damage, broken rods and personal injury are everpresent risks.
In some cases sewer cleaning machines are operated in the reverse mode. The sewer rod is passed through a blockage and a cutter tool attached to the rod. The blockage is then cleared by drawing the rod toward the machine until the debris is cleared. This method may be prefered when the blockage is upstream from the machine.
Therefore an object of the present invention is freeing the process of the removal of obstructions from blocked and clogged sanitary systems from the judgment of the operators. It provides a substantially sure-and-simple operation that eliminates the need for experienced sewer cleaning machine operators. The machine supplies the equivalence of experience.
Another object of the present invention is to provide a sewer cleaning rodding machine for dislodging roots, debris and other stoppages causing material easier, faster and more economically. This object is achieved through an automatic sewer rod feeding concept which increases efficiency, improves performance and substantially eliminates operator error.
Yet another object of the present invention is to provide an automatic sewer cleaning rodding machine which will automatically advance the rod at a suitable rate up to some predetermined resistance. The system automatically retracts the rod when the predetermined resistance occurs. This resistance may be occasioned by an excessive resistance to advancement of the rod.
Still another object of the present invention is to provide a system to select predetermined rod forces and speed which are locked to prevent tampering by inexperienced or unauthorized personnel.
Yet another object of the present invention is to provide an automatic sewer rodding machine which automatically reverses rod travel when some obstruction excessively resistes the forward movement of the tool. The tool is rapidly retracted to a preset limit; then rod forward travel is again automatically reversed to direct the tool back into the stoppage and this procedure is repeated until the obstruction is dislodged and the tool moves to the next obstruction or blockage.
Another object of the present invention is to provide a machine in which the primary hydraulic rod feed operational mode is reversible. This permits operation in a withdrawing mode to clear debris blocking a sewer upstream by drawing a cutting tool toward the machine from beyond the blockage until it is dislodged and washed away.